Vaccine Safety Research

No vaccine is completely, 100% safe. Each one has potential side effects, some possibly fatal. No one has ever said otherwise. But here’s the good news: These severe side effects seem to be extremely rare. Most infants and children go through the standard series of vaccines with few or no apparent problems at all. Yet some vaccine critics believe that there may be side effects that don’t show up for years and that the current system for monitoring and discovering such effects is inadequate. Truthfully, when I reviewed all the safety research on vaccines, I found one thing lacking. No one has ever published a thorough statistical analysis on the actual risks of a severe vaccine reaction. We know these reactions happen. We hope they are rare. But what do we actually know for sure? Many studies report on severe reactions, but these data aren’t collected into one cohesive package. We don’t know the exact number of severe reactions for each or the frequency of these reactions. Parents need this information. As a doctor, I would love to have it too.

If a vaccine is found to have too high a rate of severe side effects, it is taken off the market, which has happened three times in the past twenty years. The first was the DTP vaccine (an older version of DTaP), which was suspected to cause shock / collapse or extreme high-pitched screaming and high fevers for days. We stopped using it in the late nineties. Next was the live-virus oral polio vaccines, which could actually cause paralysis. We stopped using this vaccine in around the year 2000. The third was the rotavirus vaccine RotaShield. In 1999 research suggested that it might cause life-threatening intestinal blockage after it was given to hundreds of thousands of infants during its first year on the market (newer rotavirus vaccines haven’t been proven to cause this dangerous side effect).

The notes below are from “The Vaccine Book” by Dr. Robert Sears (October 2007; pages 177 – 179), which provides much more detail. Some sections are copied verbatim, paraphrased or summarized.

Besides trying to assess vaccine versus disease risk, critics of vaccines cite another major issue when it comes to safety research. They worry that each new vaccine that comes out isn’t adequately researched for long-term safety. For example, a new medication goes through many years of trials in a select group of people to make sure it is safe. These subjects undergo extensive blood testing and physical evaluations over many years. If nothing severe or common shows up, the medication is then released for general use.

Vaccines, on the other hand, don’t receive the same type of in-depth short-term testing or long-term safety research. The original test subjects aren’t monitored for many years to see if any long-term side effects develop. Their blood isn’t tested to check for internal toxic effects. Doctors don’t do physical exams to look for problems. Most vaccine side effects are monitored via parent questionnaires. Critics worry that many chronic diseases and other physical and mental problems like ADHD, chronic fatige, diabetes, allergies, asthma, learning disorders, and autism are triggered by vaccines. I haven’t found any solid research to support this contention. When I reviewed numerous studies, I did find some that show a possible link between a vaccine and a chronic disease. Examples include the HIB vaccine and diabetes, the hep B vaccine and multiple sclerosis and rheumatoid arthritis (see “Resources,” pages 252). However, I also found many studies that conclude that there isn’t enough evidence to prove a link, and these studies are definitely in the majority. But there is something missing from all this research. It is limited to animal studies, population comparisons between countries that use a vaccine and those that don’t, and analysis of reported reactions (which can’t be proven to be caused by a vaccine). No one has simply followed a selected group of vaccine test subjects for twenty years to see what problems develop.

From a mainstream medical journal, Vaccine, which studied the MMR-autism connection, the report concluded that there was no link between the two, but the doctors in the study stated that “the design and reporting of safety outcomes in MMR vaccine studies, both pre- and post- marketing, are largely inadequate.” (See “Resources” , page 256)

Overall, vaccines are generally safe, with some common but mild side effects and some serious but very rare reactions. We know that the diseases themselves can kill. Death and permanent disability from diseases would be a significant problem if we didn’t have vaccinations. When vaccines do cause occasional serious permanent reactions, that is tragic. For now, it’s up to you to understand the entire issue as thoroughly as possible so you can feel comfortable with your choices.

When pre-licensing trials are done on vaccines, researchers typically observe the study participants for hours or several days, and only occasionally for a few weeks or longer, to note any adverse reactions to the product. Such abbreviated methods may be appropriate for determining reactions such as injection site swelling or fever, but autoimmune responses may take months, even years to emerge. Therefore, because these reactions are rarely seen during testing, the vaccines are ruled “safe.” This approach brings to mind the words of Walter Spitzer, M.D., professor emeritus of epidemiology at McGill University, who, when commenting on vaccine safety, said, “There is no problem if you do not look.

… Marcel Kinsbourne, M.D., a pediatric neurologist, explained to the Committee on Government Reform on August 3, 1999, on the subject of vaccine safety that virus particles, such as those injected in a measles, mumps, rubella, or chicken pox vaccine, can remain dormant for months or years before they trigger a disease. Even though damage may be occurring to a child’s developing nervous system and brain, says Kinsbourne, many of those injuries may not be noticeable until much later, when they manifest as conditions such as developmental language problems, attention disorders, and cerebral palsy.

… The damaging effects of vaccines on the immune system can be long lasting. A study in the Journal of Infections Diseases looked at the long-term effect of the measles vaccines on interferon production. Interferon is a chemical produecd by white blood cells that helps makes the body resistant to infection. Interferon production is stimulated when the body is invaded by a virus. In the study, one-year-old infants given the measles vaccine had a dramatic decline in alpha-interferon production, which means the immune system was suppressed. This reduction in their immune system’s ability to respond optimally to increasing infectious organisms was observed for one year before the study was ended. Some investigators are concerned that long-term suppression of the immune system may make it difficult or impossible for the body to respond normally to disease and thus set the stage for self-destruction.

One Organization Investigates

In 1986 federal legislation commissioned the Institute of Medicine, National Academy of Sciences, to create a Vaccine Safety Committee to review the medical literature for evidence that vaccines can cause injury and death. The committee found eighteen hundred relevant articles, but its screening criteria for establishing a cause-and-effect relationship between a vaccine and reported adverse reactions were very rigid, requiring expensive case-controlled studies to prove the injuries had been caused by a vaccine. Because these costly studies had not been done, the committee announced that for many of the serious health problems reported to be associated with vaccination the evidence was “inadequate to accept or reject a causal relation.”

Yet even the committee could not ignore some of the evidence and acknowledged that brain inflammation and several autoimmune disorders could result from vaccines. Those autoimmune disorders include brachial neuritis and Guillain-Barree syndrome, which can occur after tetanus, DT and live polio vaccines; thrombocytopenia (destruction of blood platelets responsible for blood clotting) after MMR, and acute and chronic arthritis after rubella vaccination.

– The Vaccine Book? (2001); pages 80-82

Studies in animals and cells can be quite misleading. For example, in the 1950s, researchers found that hamsters injected with SV40 — a monkey virus that had inadvertently contaminated early lots of polio vaccine — developed large tumors under their skin… But many epidemiological studies performed during the past fifty years have clearly shown that SV40 virus doesn’t cause cancer in people. Studies in hamsters, although frightening, weren’t predictive. In the 1960s, researchers found that hamsters injected with adenovirus — a virus that causes colds, pneumonia, and bronchitis in people — got cancer. If these hamster studies were revealing, then people infected with adenovirus should at higher risk for cancer. But they’re not. In the 1970s, researchers showed that laboratory cells exposed to large amounts of formaldehyde became cancerous. But people who work with formaldehyde, like morticians who use it to preserve dead bodies, aren’t at greater risk of cancer…

In each of these cases, biological studies of animals didn’t predict what was happening in people. Laboratory studies can also work the other way; instead of sounding a false alarm, they have been falsely reassuring. For example, in the 1950s, researchers were interested in making a vaccine to prevent polio. The vaccine, pioneered by Jonas Salk, was made by inactivating polio virus with formaldehyde. After it was licensed, five companies stepped forward to make it. One company, Cutter Laboratories of Berkeley, California, made it badly. Because Cutter hadn’t completely inactivated its vaccine, more than 100,000 children were inadvertently injected with live, dangerous polio virus. Seventy thousand got milk polio, 200 were permanently paralyzed, and ten were killed. It was one of the worst biological disasters in American history. Before releasing its vaccine, Cutter had tested it extensively in cells, mice, and monkeys to make sure it didn’t contain live polio virus. But the laboratory studies had been falsely reassuring…

A more recent example can be found in Merck’s AIDS vaccine trial, suspended in November 2007. The vaccine, which had been remarkably effective in mice and monkeys, failed miserably when tested in people…

In 1939, Alton Ochsner, a cancer surgeon in Louisiana, was the first to propose that cigarette smoking caused lung cancer. Researchers tried to prove Ochsner’s theory in laboratory animals, but results were inconclusive. Studies in people told a different story. In the early 1950s, two epidemiological studies, one published in the Journal of the American Medical Association and the other in the British Medical Journal, clearly showed that people who smoked cigarettes were at greater risk of lung cancer — and the more they smoked, the greater the risk. Tobacco industry representatives refused to believe it, reasoning that because epidemiological studies were only “statistical,” they didn’t prove anything. The truth, they claimed, lay in laboratory studies (which had been inconclusive), not in epidemiological studies (which had been damning). But Bradford Hill, the lead investigator on the British study, disagreed: “In this particular problem, what experiment can one make? We may subject mice or other laboratory animals to such an atmosphere of tobacco smoke that they can — like the old man in the fairy story — neither sleep nor slumber. And lung cancer may or may not develop to a significant degree. What then? We may have strengthened the evidence, but we must, I believe, invariably return to man for the final proof.” Further epidemiological studies consistently showed that although lung cancer caused by cigarette smoking was rare, affecting less than 1% of those smoked, it was real. The results of these epidemiological studies no longer allowed an industry that wished to believe smoking didn’t cause cancer to hide behind laboratory studies that had proved worthless.